About 13 percent of the 7,000 traumatic work-related deaths in the United States each year are assault-related. The number of nonfatal serious injuries from assault related causes while work is unknown. The overall Goal of the proposed research is to Understand the Magnitude and Identify the Determinants of fatal and non-fatal work-related assault injuries. To accomplish this goal, our specific aims are: 1) to estimate the incidence rates of fatal and nonfatal and work-related assault injuries in four Southern California counties; 2) to identify individual occupational and environmental predictors of fatal and nonfatal hospitalized work-related assault injuries in selected high-risk occupations in four Southern California counties. There is virtually no information available on the magnitude, scope, occupations at high risk, or individual, environmental, or work-related predictors of risk. Hence, the research design is in two parts: an incidence study to measure risk in a number of important sociodemographic occupational and industrial parameters; and, second, a case control study to identify risk factors for fatal and nonfatal assaultive injuries and to estimate their effects on the outcomes. Using coroner's records and coroner-generated death certificates, police reports, and injury surveillance, we will identify, specifically, fatal and nonfatal cases, combine this information with the 1991 census, and then carry out a case and matched place-at-work control for approximately 200 of the cases identified. The case-control component will focus on High Risk Occupations and Industries such as convenience stores, gas stations, liquor stores, bars, and restaurants, taxicabs, and delivery trucks. One rationale for the design is to maximize the availability of 1991 census data and to focus on in-depth studies of cases of relevance to the objectives. Factors associated with the occupational setting and the place of work, with the employee, with the environment, and exposure events will be assessed, and their affects on the outcome will be measured. From the overall results, we should be able to not only to estimate precisely fatal and nonfatal incidence rates, but we should also be able to identify, for the first time, in a scientifically conducted study, risk factors and their potential effects on exposure. The applications of these findings are generalizable to similar occupations throughout the United States.